Radiotelegraphy



June#v 3 192.4.

p 1,496,243 F. s. MccuLLouGl-L RADIQTELEGRAPHY Filed July 7. 19'19- 2 Sheets-Sheet 1 lllllllllll vvgawro y a6 Aims Arrom June 3 1924. 1,496,243

F. s. MccuLLo'UGH RADIOTELEGRAPHY vlFiled July v, 191s 2 snnis-sheez 2 -Almmlnim WWW/WWW Q FLL (lluwwm l 4Patented June 3, 1924.

UNITED STATES .PATENT oFmcE.

FREDERICK S. MCCULLOUGE' OF CLEVELAND, OHIO, -ASSIGNOIR.. TO GLENN L. MARTIN', OF CLEVELAND, OHIO.

RADIOTELEGRAPHY.

Application tiled July 7,

v which the following is a specification, the

various mechanical forms in whichthel principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it'from other inventions.

My invention relates to systems of radio telegraphy, and more particularly to systems at, receiving stations for determining the direction of incoming electro-magnetic waves, so that the location 'of the transmitting station may be ascertained.

In the directional systems hitherto used, there have been employed large loops or coils of wire for the receiving antenna, these loops being usually flat coils wound on a square frame having sides of several feet or several yards in length. While directional loops of such size are satisfactory for permanentland stations, it can be readily seen that there are grave objections to them for portable stations such as those on a small boat, and more particularly on an airplane. For the latter, it is-essential to have the apparatus in as compact form as' possible, and by my system I can provide means of eX- tremely small dimensions, which will satisfactorily determine the direction of a transmitting radio station. At the same time, I provide for the detection of the incoming oscillations.

My receiving elements comprise coils enclosed in anevacuated tube, together with such other elements as are necessary to carout my invention, as will appear more particularly from the detailed description of my system, together with the drawings.

The annexed drawings and the following description set foren in detailV` certain means embodying` my invention, thev disclosed means, however, constituting but one of the principle of my invention is employed.

In the drawings:

Figure l'showsa general view of the circuits in my system, together with the ele- `ments of my inventionin diagrammatic form;

Figure 2 shows a view of my evacuated tube containing a single unit of coils and fil- 1919. Serial No. 308,978.

ament, and a diagram of a modified form of my circuits.

Figure 3 shows a view o f one of mytubes containing two units of coils and filaments, and a modified form of circuits.

Figure 4 shows an arrangement of circuits and elements of my invention where I desire to amplify the received oscillations.

In Figure 1, l is a coil having a number of turns enclosed in an evacuated tube and forming one of my receiving elements. 2 represents a second coil also enclosed in the same tube and inductively related to the irst coil. 3 represents a filament also enclosed in the evacuated tube. A line is drawn about these three elements to indicate that they lare all in one evacuated tube. 4 isa battery for heating the filament 3.- 5 is a variable condenser between the coils 1 and 2'. 6 is a variable vcondenser between the coil '2 and the filament 3. 7 is a variable inductance in circuit with the coil 1. 8 is a variable Ainductance in circuit with the coil 2. 9 is a variable battery by means of which current is sent 'through the tube from the coil 1,

through the coil 2, to the filament 3. The battery 9 need not necessarily be variable, and similar batteries are shown not variable in some of my other figures. 10 is a telephone for indicating changesl or signals in the circuit including the. tube and the battery 9. 11 is a variable inductance coil in circuit with the lament 3,

In Fi re 2, 13 is an evacuated glass tube or vesse 1 is a coil within the tube, with its terminals passing outside. 2is another coil inside coil 1, with its terminals passing outside. These coils may be made of nickel or Aof copper, or of any other suitable material. The .return leads from thefar ends of the coils-to the base ofthe tube are shown outside the coils, close to the wall of the tube, s o as to avoidconfusin in the drawing, but in' practice they are generally carried back inside one or both coils, covered by small glass tubes, or other suitable insulation. 3 is in the filament.

In Figure 3, 17 is an evacuatedtube or vessel, 1 is a coil .with terminals leading outside of the tube. 2 is a coil inside'the coil 1, .with its terminals leading outside 4of the tube.j 3 is a 'filament inside of coil 2, with its terminals leading outside of the tube.

14 and 15 are coils, and 16. is a filament, similar, respectively, to coils 1 and 2 and the lilament 3 just described, and placed inside ithe same tube with terminals leading outside of the tube. 5 and 6 are 'variable condensers. 4 is a' battery for heating the ilament'3, and 12 is a variable resistance.

' 9 is a' battery. 52 is a transformer for transtransferring the oscillations inside the coil 31 ferring` the oscillations of thev circuit containing battery 9, coil 1 and filament 3 to coil 15 of the second unit, whence they are impressed, in amplified form, upon the circult including coil 14, filament-16, battery 57 and the'telephone receiver,- or other indicating device 58. 53 is a' variable. resistance and 54 a battery for heat-ing filament a variable condenser between coil 14 and coil 15, and 56 is a variable condenser Abetween coil 15 and filament L16. The-first unit in this tube is used for receiving the `incoming electro-magnetic waves, andthe second unit is also used for this purpose and at the same time acts as an amplifier of the oscillations received by the first unit, bydneansofthe appropriate circuits and connections shown. f

In Figure 4, 1 isa coil enclosed in an evacuated tube. 2 Vis a second coil linJ-the sametube." ``3 is a filament also inthe tube. 4 is a battery su-p' lying current tothe-filament.- 5 is a variable condenser'between coil 1 and coil 2. 9 isa variable battery. 12 is a variable resistance for regulating'the-current in the filament. 18 1s a 'battery for keeping coil 2 e1ectro.-ne`gative,'and 19 is a variable high resistance acrossY battery 18, which acts as a potentiometer. 20 is a transformer for transferring the oscillations in the circuit comprising coil 1, filament 2', and

battery 9,'to coil 22 in the next unit. lCoil `22 is in an evacuated tube Awith coil.21 and filament 23. 24 is a battery and 25 a variable resistance. 26 is a battery and 27 a high resistance or potentiometer. 28 is a battery. 29 is a variable condenser between coils 21 and 22.' 30 is a transformer for in the circuit comprising coil 21, lament 23 and. battery 28, to the coil 32 in the next unit oriamphfying stage Coil 32 is in an evacuated tube and outside of filament 33, also enclosed therein. and 35 a variable resistance.4 36 isa battery and 37 a potentiometer for keeping coil 32 34 isy fr battery electro-negative. 38 'is a battery. -39 is a variable-condenser between coils 31 and 32. 40 is a transformer for transferring oscillations in the circuit containing coil 31, fila- 42 in the next ment 33 and battery 38, to coil Coil 42 is beunit or amplification stage.

tween coil 41 and ilament'43 in an evacu- 'ated tube. 44 is a battery and 45 a variable resistance. 46 isa battery and 47 a variable high resistance or potentiometer, for the purpose of keeping coil 42 electro-negative. 49 is a Variable ,condenser between coils 41 and 42. 50 is a variable condenser in circuit with the transformer 40 and coil 42. The principal function of condenser 50 is to assist in tuning the circuits in this final stage. 48 is a battery for supplying current to the circuit containin ment 43, :and the sensitive ga vanometer 51.

The sensitive galvanometer 51 is one means of indicating the amplified oscillations received, but 1t may be replaced by other forms of indicator. ciple of indicating by visual means the strength of the oscillations received on directionaLreceivers. This eature is not a part of the present-invention, rately described and claimed in my app tion In order that all the coils in all the tubes coil 41, lila- It involves the prin-Y but is sepav lica' Serial No. 313,161, filed July 25, 1919.

may contribute to the fullest extent to the diy mum sound isheard in the telephone re-v ceiver, 'or the maxirmmr deflection' isifobthe served on the 'galvanometen or until'the maximum effect is obtained with any other indicating means I may emplo It has been `found that this maximum e ectis produced when the planes of the individual turns of the coil or coils are as nearly as possible in the direction of'the transmitting station. As the coils are helical in form, the individual turns do not lie in true planes, but when the axis of eachcoil is at-right'angles to the direction of the transmitting statlon, the average effect is greatest. Instead of the position for maximum effect, the' position for lminimum-effect can be found, which willbe at rightangles to the former. position. The minimum -eifect positionis sometimes 'more readily determined. I can also arrange my coils 1n' a plane, in the form of a a't spiral, either circular or rectangular, but for mechanical reasons the ordinary helical frm of thefcoilss preferable, es pecially from the standpoint of tube manuacture.'

Taking Figure l as an example, the incomingwaves a' 2, which have a cumulative effect upon each other, and the presence of these incoming waves is detected by means of the electron current flowing from the filament 3 to the coil l, and the variations in the electric cur-l rent thereby caused in the circuit through the telephone 10, are indicated by the latter.

The capacitance of this system can be varied at will by means of the condensers 5 and 6, which are outside the tube. The induc- `tance of the system can be increased by increasing the number of turns in the coils l and 2, and when it is desirable to have greater inductance than can be obtained with the limitations of space inside the tube, additional inductances outside the tube, such as shown at 7 and 8, can be connected conductively or inductively with the coils in the tube. One means for obtaining this additional outside inductance is to provide coils outside of the tube in inductive relation to those inside and placed as close to them as poss-ible. By means of this variable capacitance and inductance, the system can be tuned` to any desired frequency or Wave length. y

By properly choosing the values of my electrical quantities and proportioning my elements, I can secure regenerative effects in my system, which increase the-strength of the received oscillation.

The outside inductance should not be so great as to interfere with the proper resonance effects of the interior elements, and, in general,- the inductances, the capacitances and the other electrical features of the whole system should have such valuesand should beso proportioned that the best effects are produced. These values and proportions I can determine for each system.

In the form of my invention shown in Figure 3, two receiving and detecting units are placed in the same tube, and one of them amplilies the oscillations received by the other, and at the same time assists in obtaining the directionalefi'ect.

Additional tubes can also be provided, either for increasing the inductance, or for amplifying the received oscillations, or forv both, as shown in Figure 4.

The tube containing my receiving elements need not be more than one inch in diameter, nor more than three inches long, but I do not limit myself to any particular size. With this system of mine, itis not necessary to have any separate antennae, and the elements in my tube constitute a means for detecting the received electrical oscillations, as well as for determining the direction of the incoming electro-magnetic Waves.

It will be seen from the above description that my system provides an extremely compact means for determining the direction of a `radio transmitting station, and is especially applicable to airplanes or small craft, and can even be used in a portable set which can be carried on ones person.

I do not confine myself to the exact rconstructions and arrangements herein described, but may also employ other means well known to those skilled in the art,'but what I claim and desire to secure by Letters Patent is:

l. A radio receiving system comprising two collector coils and a. heated filament, enclosed in an evacuated vessel.

2. In a radio receiver, acircuit including an Vionizing means and having a collector coil, and an evacuated chambercontaining said ionizing means and saidcoil.

3. A radio receiving system including a source of' ionization, a collector' coil surrounding said source, and a second collector coil surrounding said first coil, the axes of both coils being parallel, said source and said coils being enclosed in an evacuated vessel. i

4. A. radio receiving system, including a source of ionization, a collector coil surrounding said source, and a second collector coil surrounding said first coil, said coils having a common axis, said source and said coils being enclosed in an evacuated vessel.

5. In a system of radio transmission, directional receiving means including two co1'- lector coils enclosed in an evacuated tube.

6. A radio receiving system comprising .two collector coils enclosed in an evacuated vessel, said coils being in inductive relation 

